‘Pandemic of our time’: WHO leader talks AIDS threat

Christopher Dye, director of health information in the World Health Organization’s Office of HIV/AIDS, spoke about global health policy to a full audience in Dodds Auditorium on Monday afternoon.

Dye began with a disclaimer that he was representing his personal views of how science should be translated into action, rather than those of the WHO. A slide projected onto the auditorium’s screen featured photographs of prominent advocates and opponents of disease reform who constituted a “patchwork of heroes and villains” in the history of global health. “What gets done in public health,” Dye said in reference to the slides, “[comes] down to the people who are doing it.”

When people talk about plagues and pandemics, Dye said, they generally refer to diseases such as cholera, the plague and influenza. It is seldom that true pandemics like tuberculosis and HIV are included in this conceptual list, even though “AIDS ... is the pandemic of our time,” Dye said. The largest spike in media attention to tuberculosis between August 2006 and August 2009, he added, came in the wake of the decision by Andrew Speaker, a Georgia lawyer, to travel throughout Europe on his honeymoon despite the fact that he had been diagnosed with tuberculosis beforehand.

With this observation, Dye addressed the emerging problem of drug resistance, an issue which has recently raised concern in the United States and other developing countries. Multi-drug-resistant tuberculosis, or MDR-TB, a variant of the disease in which patients become resistant to the two primary first-line anti-tuberculosis drugs, has been on the rise worldwide, most notably in former Soviet nations and in China.

Antibiotic resistance develops most frequently among those who have not been properly treated after first diagnosing the disease, Dye said, citing the difficulty of adhering to long and complicated courses of medical treatment, which require combinations of drugs taken over a period of months, as a factor contributing to the prevalence of resistance cases. If a patient misses one dose of a prescribed drug, resistance can easily occur.

Extensively drug-resistant tuberculosis, or XDR-TB, in which patients become resistant to second-line tuberculosis drugs, was also presented as cause for concern. In addition to the fact that “X is easily the most intimidating letter of the alphabet,” Dye joked, XDR-TB typically results in high mortality rates. In the first documented case of XDR-TB at a hospital in Tugela Ferry, South Africa in 2005, 52 out of 53 patients admitted to one ward died within 16 days of sputum collection, Dye said. All were HIV-positive as well.

Though drug-resistance may seem frightening, Dye noted, it makes more sense from a global health perspective to devote resources to drug-sensitive people first, since the death of a drug-resistant person stops the train of transmission. The current WHO plan for drug-resistant TB treatment constitutes “an enormously ambitious and extensive program,” Dye said, but at the same time “the results of our calculations suggest: Don’t do it at the expense of basic tuberculosis control.”

The prognosis for the treatment of drug-sensitive people is brighter, Dye added, because “we’re dealing with benign epidemics so far as ... drug sensitive forms of TB are concerned.” In most settings, all TB strains are on a slow path to elimination, and so greater efforts are needed to speed the process.

Dye also spoke about current policy on the treatment of HIV, which afflicts many victims of tuberculosis as well. Though from a policy perspective, “What you need are simple rules [about the white blood cell count criterion for receiving treatment] ... because they won’t be implemented if they’re not simple,” in reality the white blood cell count in infected individuals varies widely between regions, Dye said. This variability, Dye added, should be taken into account by laws that stipulate the conditions for treatment.

Despite having spent 30 years and $150 billion on worldwide HIV campaigns, the fact that 34 million people are currently infected with the disease indicates that policy is “having hardly a dent in the epidemic at the moment,” Dye noted.

The use of antiretroviral therapy as a prophylactic, Dye explained, could help to curb transmission. Though these drugs are generally used to treat HIV, several studies have shown their efficacy in prevention as well. Annual testing and subsequent treatment for people in countries where HIV is most prevalent could ideally cut transmission by a factor of eight and contribute substantially to the eventual elimination of the disease, he said.

One of the final issues considered was treatment for those afflicted by both tuberculosis and HIV. Combining medical intervention procedures could cut deaths due to tuberculosis among HIV-infected people by as much as 80 percent, Dye said, and save about one million lives by 2015.